During prolonged operation, the end face of the internal mixer, a crucial component in rubber processing, experiences wear, resulting in an increased gap between the mixing chamber and the end face. This gap can lead to material leakage and reduced mixing efficiency, negatively impacting rubber properties. To address this issue, researchers have introduced dynamic covalent bonds into the molecular rubber chains, giving the material self-healing properties. This advancement is essential for extending rubber lifespan and reducing production costs. One common approach involves adding methacrylic acid (MAA) and excess zinc oxide (ZnO) to create ionic crosslinking networks, limiting covalent crosslinking and enabling in-situ polymerization of MAA/ZnO, resulting in self-healing capabilities. However, the strong acidity and corrosive nature of MAA can cause metal wear. In our study, we mechanically blend MAA with ZnO to produce zinc methacrylate (ZDMA)/rubber composites. We investigate the in-situ synthesis mechanism of MAA and ZnO and assess the impact of MAA on the friction and wear of the internal mixer's end face. Our findings reveal that ZDMA ion pairs form an “ion cross-linked network” within the rubber chain, hindering SiO particle dispersion and increasing aggregation within the rubber matrix. This compromises dispersion and leads to abrasive wear from SiO particles, corrosive wear from high-temperature water vapor, and corrosive wear from MAA. Additionally, excessive ZDMA self-polymerization alters SiO particle agglomerates. The strong acidity of MAA and the “ion cross-linked network” within the rubber matrix significantly affect SiO particle dispersion, friction coefficients, metal surface roughness, and metal wear. Our comprehensive analysis, including SEM, dispersion, RPA, metal surface morphology, and CSM friction wear tests, identifies the optimal cross-linking effect with the addition of 15 phr of MAA, resulting in a well-defined “ion cross-linked network” within the rubber matrix, enhancing rubber performance. However, SiO particle dispersion is compromised, leading to increased agglomeration and heightened metal wear.

中文翻译：

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甲基丙烯酸（MAA）/氧化锌（ZnO）原位合成反应对复合过程中金属摩擦磨损的影响


密炼机作为橡胶加工的关键部件，在长时间运行过程中，其端面会受到磨损，导致密炼室与端面之间的间隙增大。该间隙会导致材料泄漏并降低混合效率，从而对橡胶性能产生负面影响。为了解决这个问题，研究人员在分子橡胶链中引入了动态共价键，赋予材料自修复性能。这一进步对于延长橡胶寿命和降低生产成本至关重要。一种常见的方法包括添加甲基丙烯酸 (MAA) 和过量的氧化锌 (ZnO) 以创建离子交联网络，限制共价交联并实现 MAA/ZnO 的原位聚合，从而产生自修复能力。然而，MAA的强酸性和腐蚀性会导致金属磨损。在我们的研究中，我们将 MAA 与 ZnO 机械混合以生产甲基丙烯酸锌 (ZDMA)/橡胶复合材料。我们研究了MAA和ZnO的原位合成机理，并评估了MAA对密炼机端面摩擦和磨损的影响。我们的研究结果表明，ZDMA 离子对在橡胶链内形成“离子交联网络”，阻碍 SiO 颗粒分散并增加橡胶基质内的聚集。这会损害分散性并导致 SiO 颗粒的磨料磨损、高温水蒸气的腐蚀磨损以及 MAA 的腐蚀磨损。此外，过度的 ZDMA 自聚合会改变 SiO2 颗粒团聚体。 MAA的强酸性和橡胶基体内的“离子交联网络”显着影响SiO颗粒分散度、摩擦系数、金属表面粗糙度和金属磨损。 我们的综合分析，包括 SEM、分散度、RPA、金属表面形貌和 CSM 摩擦磨损测试，确定了添加 15 份 MAA 时的最佳交联效果，从而形成明确的“离子交联网络”在橡胶基质内，增强橡胶性能。然而，SiO 颗粒的分散性受到损害，导致团聚增加和金属磨损加剧。